> it only applies if it is intended to and corruptly accepted as an influence on official decision-making.

The majority opinion argues that this is one of the primary differences between a bribe and a gift of gratitude.

> A gift as a thank-you, post-hoc, where the prosecution cannot prove the gift was part of an effort to "corruptly" influence a prior decision, was always fine under any interpretation.

No, which is a large part of this whole argument. The interpretation the government used and was (indirectly) backed by the minority opinion, was, that the statute would not cover "innocuous or obviously benign" gratuities. But what counts as "innocuous or obviously benign" was never established. And this "innocuous or obviously benign" line is EXACTLY what distinguished between whether a gratitude was accepted with a corrupt state of mind.

And that's where we arrive back at the core of the problem.

For a bribe, the question of whether or not a corrupt state of mind existed can be judged at minimum by if the official act was corrupted. Usually this standard doesn't exist for gratitudes. These do not require a corrupt state of mind to be criminal, but their criminality derives solely from the heightened standard of responsibility of an official when performing official duties. Just like a heightened standard of responsibility when operating a motor vehicle or carrying.

> If students said "if you give us a good grade, then we'll give you a Best Teacher Ever mug," that is functionally identical to a bribe but is now legal.

Not really a good example, because unless that's something like a theater performance there is basically no way forward from this, which could end with the teacher handing out good grades and receiving a mug from these students without this scenario becoming bribery.

And gratitudes do not become legal in general. It's just that the involvement of the federal government ends and states are now free to handle such cases however they think is appropriate.